Manufacture of salt.



B. I'. MGTBAR.

MANUFACTURE 0F SALT.

APPLICATION FILED Nov. 4, 1907.

Patented Sept. 7,1909.

2 SHEETS-SHEET 1.

0mm, v Mac ,i

@gdm

ANDREW, e. GRAHAM on.. mrmLmmGRAPNiRS. wAsMmm'on. u. c.

B. P. MGTEAR. MANUFAGTURE 0F SALT. APPLIGATION FILED Nov. 4, 1907.

Patented Sept. 7, 1909.

2 SHEETS-SHEET Z.

aww. y?

UNITED sTATEs PATENT oEEroE.

BALFQUR FRASER lVIcTEAR, 0F LEA` GREEN, VIA RAIN HILL, ENGLAND.

MANUFACTURE 0F SALT.

Specification of Letters Patent.

Patented Sept.v '7, 1909.

Application filed November 4, 1907. Serial No. 400,598.

To all 'whom tt may concern:

Be it known that I, BALEOUR FRASER M0- TEAR, a subject of the King ofGreat Britain and Ireland, residing at St. Michaels House, Lea Green,via Rainhill, in the county of Lancaster, England, have invented certainnew and useful Improvements in the Manufacture of Salt, of which thefollowing is a specification.

rlhis invention relates to the manufacture of white or pure salt fromthe ordinary impure or rock salt in its natural condition.

Heretofore white salt has been manufactured from rock salt by meltingthe latter in an ordinary open hearth furnace and running the moltenmaterial therefrom into receptacles or converters, and after treatmentin such converters allowing it to remain in a molten state, quiescentfor a time, so that the impurities may settle out.

The object of my present invention is to produce white or pure salt fromordinary impure or rock salt in a cheaper and more efficient andreliable manner than heretofore.

The invention comprises the process and means as hereinafter describedfor purifying the molten salt.

Referring to the accompanying sheet of explanatory drawings z-F igure 1shows in sectional elevation and Fig. 2 in side elevation, with certainparts omitted for the sake of clearness, one convenient form ofapparatus which I employ in carrying my invention into effect.

The same reference letters in the two views indicate the same parts.

The rock salt to be treated is rst melted in an open hearth or otherfurnace and is then drawn olf into suitable receptacles or converters.One of such converters is illustrated in the accompanying drawings. Itconsists of an outer casing as a, lined with rebrick and provided with adetachable bottomless liner b having a hood c at its upper end. Theconverters a are mounted on wheels Z and arranged to run on a track c.Before they are filled with the molten material from the meltingfurnace, the' converters are suitably heated by flame and hot gases.After the converters a are filled with molten salt, I pass into each.one or more agitators. One convenient construction of the agitators isillustrated in the drawings. Upon vertical guide bars f is slidablymounted a cross head g from which are suspended spindles m, as shown,carrying beaters or paddles h. The latter rotate in unison, being gearedtogether by spur wheelsz' driven from an electric motor j throughsuitable gearing.

I do not however limit myself to any particular means for driving thepaddles or beaters. Vhen the beaters are in operation, the currentsinduced in the molten salt will intercept and break up one another andso cause the impurities to fall to the bottom of the converter. Duringthe agitating process the converters may be kept at a high temperatureso as to aid the residual matter to separate out from the salt, and limeand niter in quantities of about 0.1 to 1 per cent. may be added to themolten material to oxidize any oxidizable impurities.

After the treatment above described which generally will be found tohave completed purification in from 10 to 15 minutes the cross head f/is lifted by means of the chain le, the paddles or beaters l1., beingthus raised out of the converter. The detachable liner 5 is then removedfrom the converter and carries with it any discolored salt which mayhave congealed thereon. The greater part of the sediment contained inthe molten material will now be found to have settled at the bottom ofthe converter. The converters are now drawn slowly along the track, andby such motion a gentle agitation is given to the molten salt; or, ifdesired, the rails of the track may be indented as shown in Fig. 2, orother means may be adopted for setting up a gentle agitating orvibratory movement which greatly assists in the deposition of theresidual matter or impurities. After the salt has been sufficientlycooled, it is removed as a block from the converter and the impure lowerportion of the block can be readily knocked off.

I may if desired arrange the agitators h to be rotated in one directionfor a short time and then in a reverse direction, and also if desired tobe automatically raised and lowered in the molten salt by means of thechain 7c while they are rotating. They may also be used in the meltingfurnace, but this will not as a rule be found necessary or desirable.

I may use any number and arrangement of paddles or beaters in oneconverter. For example, in very large converters, I may employ four setsofl such paddlesvor beaters and arrange their supporting spindles to bedrive'n from a spur wheelarranged in\the The paddlesv pivotally attachedto their supporting barsl or spindles 15, 15 so that they can move intorajhorizontal vposition by centrifugal force when they are rotated, and,when at rest,

hang in a vertical position.

By the use of my process, I dispense with y hot air stoves, blowingengines and the'like which have'previouslybeen used for purifyingymolten salt, and obtain amore efficient,

Ydurable and reliable apparatus than has heretofore been possible, asthe excessively hightemperatures which have been found necessary withthe before mentioned process have caused great wear and tear on theparts of the apparatus.

Having now described my invention, what I claim asnew and desirel tosecure by Letters Patent is l. The process of purifying rock salt,consisting in melting the said salt and subjecting the molten mass tothe action of agitators rotated thereiny whereby the salt and itsimpurities are separated, substantially as described.

2. The process of purifying rock salt,con sisting in melting'the saidsalt, drawing the molten material into a converter, adding an oxidizingmaterial to the molten mass, and subjecting the said mass to amechanical agitation whereby the said salt and its impurities areseparated, substantially as described.

'3. The process of purifying rock salt, consisting in melting the saidsalt, drawing the molten material into a converter, subjecting themolten mass to the action of agitators rotated'therein, whereby' thesalt and its impurities are separated, and imparting a vibratorymovement tothe converter andthe agitated mass whereby the deposition ofthe impurities is facilitated, substantiallyfas described.

In testimony whereof, I afliX my signature in presence of two witnesses.Y

BALFOURFRASER MC'TEAR.

Witnesses WILLIAM JOSEPH VVooDcooK, VIvIAN ARTHUR HUGHES.

